98 



MASS. EXPERIMENT STATION BULLETIN 166. 



Titration of excess alkali. 



R in the graphic formula of the fatty acids represents C and H in differ- 

 ent amounts, according to the acid, but in the proportion of CnH2n+i, 

 except in the case of unsaturated and of dibasic acids. 



Saponification Numbers of Triglycerides. 



Gltceride. 



Acetin, . 



Butyrin, 



Valerin, 



Caproin, 



Caprylin, 



Caprin, 



Laurin, . 



Myristin, 



Palmitin, 



Stearin, 



Aracliin, 



Olein, . 



Erucin, . 



Linolin, 



Linolenin, 



Clupanodonin, 



Ricinolein, 



Dihydroxystearin, 



Supplementary Notes. — The term "saponification or saturation equiv- 

 alent," as employed by Allen ^ and others, indicates the grams of fat that 

 are saponifiable with one equivalent of potassium hydroxide in grains 

 (56.108); in other words, the grams of fat saponifiable with 1 liter of N 

 potassium hydroxide. 



56108 mg. of fat 



Saponification equivalent (sq) = 



c.c. N alkali' 



Saponification number (s) 



56108 _ 

 sq 



The lower the molecular weight of the fatty acids (or esters) the more 

 alkali will be required to satisfy 1 gram, and the higher will be the saponifi- 

 cation number. The presence of free fatty acids increases the saponifica- 

 tion number, and unsaponifiable matter decreases it. The majority of oils 



' Commercial Organic Analysis, 2, pp. 15, 16 (1910). 



